Ultrastable Supramolecular Self‐Encapsulated Wide‐Bandgap Conjugated Polymers for Large‐Area and Flexible Electroluminescent Devices

Abstract

Scheme 1. Schematic representation of the supramolecular self-encapsulation strategy for wide-bandgap LCPs. A) Typical molecular model of our supramolecular self-encapsulated LCPs (SMART: Synergistically Molecular Attractor-Repulsor Theory). B) Chemical structures of the model polymer, PHDPF-Cz, together with the controlled polyfluorenes. C) Computer-generated model of PHDPF-Cz: i) axial and ii) lateral views. Schematic diagram illustrating the ideal molecular packing model for a PHDPF-Cz self-assembled superstructure, where the pendent Cz groups self-assemble into a sheath and act as an encapsulated layer to isolate the chain and inhibit the interchain interaction between π-π backbones, similar to previous studies. [47,52,53] The blue rings signify the backbone chain. The red loops indicate the Cz-threaded layers. The yellow arrow represents the 2D charge transport channel. The orange-yellow arrow denotes the penetration path for various gases, which is disrupted by the Cz-threaded layer.

Diastereoisomer‐Induced Morphology Tunable Self‐Assembled Organic Microcrystals of Conjugated Molecules for Ultraviolet Laser

“…Meanwhile, from the fluorescence excitation–emission contour plot (Figure 4D), it is easy to observe that emission peak of the rac ‐DPFOH microcrystal presented exceptionally well‐resolved structure with narrower and sharper emission peaks than those of meso ‐DPFOH microcrystals, similar to single molecular chain of polyfluorenes, such as octafluorenes. [ 36,39–41 ] Compared to the thin spin‐coated film, this red‐shifted spectra of microcrystal are associated with the strong re‐absorption and weaker intermolecular aggregation in the crystal states. Besides, combined with the analysis of weak interaction in diastereomer, due to discrete columns of supramolecular polymers in rac ‐DPFOH crystalline framework by CH…O and π…π interactions along the [100] direction, microrods exhibit spectral behaviors of single‐strand polymer with fine‐structured emission, similar to the emission of amorphous film.…”

“…[ 35 ] As displayed in Figure 1A, DPFOH with supramolecular segment (hydroxyl), repulsive steric bulk (benzene), and chiral carbons (9‐site carbon), is expected to exhibit structural diversity, according to the synergistically molecular attractor‐repulsor theory (SMART). [ 36 ] DPFOH molecules contain two chiral centers, and there are three possible stereoisomers overall—one pair of diastereomers (raceme ( rac ) and mesomer ( meso ) (Figure 1A). As we expected, both diastereomers have similar fundamental photophysical and electrochemical characteristics in solution and amorphous film, which could be attributed to their similar conjugated backbone structures.…”

Suppressing aggregation induced quenching in anthracene based conjugated polymers

“…Clearly, the detrimental effects of aggregation are essentially absent for AF8 in the solid state. Such a direct transfer of luminescence properties from solution to the solid state is remarkable for a conjugated polymer [54][55][56][57] and, to the best of our knowledge, completely unprecedented for one based on anthracene (Table S3 †). We note a slight extension of the PL tail to longer wavelengths in thin film, which we ascribe to interchain energy transfer to lower energy trap sites in the solid state.…”

Deep‐Blue Thiophene‐Based Steric Oligomers as a Low‐Threshold Laser Gain and Host Material

“…[ 13 ] Herein, we synthesized a novel Th‐based blue fluorescent steric molecule MC8‐Th with exceptional amplified spontaneous emission (ASE) behavior for deep‐blue organic lasers ( Scheme a). [ 52,53 ] It is believed that the steric unit at 9‐postion will partial suppress intermolecular aggregation at molecular level and precisely tune molecular self‐crystallization behavior. [ 13,18,30,32 ] Although it presents low PLQY value (8.8%), the spin‐coated neat film exhibits exceptional deep‐blue ASE behavior with a remarkably low threshold of 6.0 µJ cm −2 and full‐width‐at‐half‐maximum (FWHM) value of 2.6 nm under vacuum atmosphere.…”